DMD myogenic cells from urine-derived stem cells recapitulate the dystrophin genotype and phenotype

A ready source of autologous myogenic cells is of vital importance for drug screening and functional genetic studies in Duchenne Muscular Dystrophy (DMD), a rare disease caused by a variety of dystrophin gene mutations. As stem cells (SCs) can be easily and non-invasively obtained from urine specimens, we set out to determine whether they could be myogenic-induced and useful in DMD research. To this end, we isolated stem cells from the urine of two healthy donors and one patient with DMD, and performed surface-marker characterization, myogenic differentiation (MyoD), and then transfection with antisense oligoribonucletoides to test for exon skipping and protein restoration. We demonstrated that native urine-derived stem cells express the full-length dystrophin transcript, and that the dystrophin mutation was retained in DMD patient cells, although the dystrophin protein was detected solely in control cells following myogenic transformation according to the phenotype. Notably, we also showed that treatment with antisense oligoribonucleotide against dystrophin exon 44 induced skipping in both native and MyoD-transformed urine-derived stem cells in DMD, with a therapeutic transcript-reframing effect, as well as visible protein restoration in the latter. Hence MyoD-transformed cells may be a good myogenic model for studying dystrophin gene expression, and native urine stem cells could be used to study the dystrophin transcript, and both diagnostic procedures and splicing modulation therapies in both patients and controls, without invasive and costly collection methods. New, bankable bioproducts from urine stem cells, useful for pre-screening studies and therapeutic applications alike, are also foreseeable following further, more in-depth characterisation.